Stop mechanism.



J. Kim/mz.

STOP WIECHANISM.

JPPLICATGON FILED JUNE 13| 1914.

Patente@ May 30,1916.

W I MMM/a ,on the plane SH3 of Fig. l.

JHN KIEWXCZ, HYDE PARK. MASSACHUSETTS, A 5.SSIG].\.TOR TO THE EEECE BUTTN HOLE IVIACHNE COMPANY, 0F MAINE.

BOSTON, MASSACHUSETT`. .A COR'PORLTON F STDP MEClEANISll/I.

rie/inni.

Application filed .Tune 13, 1914.

To al? 'fo/1.0m 11mg/ concern.'

Be it known that l, .lonn Knlwic'i/a citizen of the United States, residing at lHyde Parla, in the county of Suffolk and State of Massachusetts, have invented een tain new and useful lmproven'ients in Stop Mechanisms, of which the following isa specification.y reference being' had therein to the acconwanying drawing. A 'f This invention relates to stop mechanisms and more particularly to a mechanical contrivance associated with the driving` mechanisms of machines of various sorts forv effecting' the stoppage thereof in a desirable manner.

in object hereof is to afford an efficient and durable stop mechanism adapted to employment with light, fast-rotating machines such as sewing machines, power driven Another object is to provide a stop mechanism which is easily controlled and operated and serves to pnomptly, yet withont shocku brinethe main shaft of the machine to rest preferably with the needles or other operatingparts of the machine at a predetermined point .in the cycle of their opera tions.

@ther objects hereof will be perceived from the hereinafter following description of an illustrative mechanisn'i embodying the principles of this invention.

To the attainment of the objects referred to the present invention consists in the novel cembimitions, arrangements, mechanisms. devices, details and other featnresillustrated or described herein.

Figure l is a front elevation of a portion of a sewing' machine en'ibodying;` a stop mechanism constructed on the principles of this invention. thc front side being' broken away to disclose the interior. Fig. 2 is ar right elevation thereof. Fig. 3 is a section lliftg. Ll is a sccA tion on the plane Ll--l-ll of Fig. l. Fig. 5 is a section on the plane 5-5 of Fig. 4i.

lhe same reference rninierals designate correspondineT parts in the. several views of the drawings.

For convenience of illustration, the gein eral type of sewing; machineillustrated in prior Patent No. 11,047,507 of December 17th. lllrf. has been selected and sach prior pat cnt may be referia-al to for the general operation of such a. machine and for various Specication of Letters Patent.

from a contirnionsly rotating shaft.

l "aftented llliay 3d, tillft.

Serial No. 844,856.

details not constituting pm" .wc the present il'ivention.

The hollow base S of the machine snp ports the stitching mechanism. which would be at the left end of the machine and for convenir-nice omitted, and the driving,T and stop mechanism which is at the right end, partly within and partly without the base. The main shaft 1U extends from the driving mechanism to the stitching niechanisin and operates the needles and cooperatingr parts.

A pressenfoot ll is shown carried at the forward end of the arm 12 of a swinging' lever the shaft 13 of which affords a pivotal bearingr and also carries a second or actnatingarm il extending' within the base 9. The arm lfi has at its extremity an ex tension l5 to permit the lifting of the presser-foot, against spring' 1G, by a` lifting part or swinging arm' 17, which is held up l by spring' 1S so that its stud 19 bears on a device or cam 20 on main shaft l() as shown. Thereby the presser-foot is raised automa tically when the .machine is stopped. ll/ hen the machine is started the arm li' is shifted to the left, so that cam Q0 will not lift the presser-foot. by means later described.

The main shaft is snppr'lrted in bearings, one of which7 2L is shown, and the shaft eX- tcnds from the interior of 'the base tlniongh its right hand wall to the exterior parts.

Referring' now more particularly to the driving` and stop mechanism, .it involves e brake device associated with the rotary shaft l0 or preferably with n hollow drum Q5 cared upon the shaft, and `Vith contacts or lugs upon the shaft and the brake device respectively, the same being adjustable rela tively endwise, that is to say longitudinally of the main shaft. The bralre device pref- `erahly comprises a. bra-kc shoe located in the inte-rior of the drinn and in the form of an arc of a circle. and the contact for operatingthe bra lie shoe is movable endwise in such n'ianner that the contact is brought into line with the contact that rotates with the shaft7 so that the braking' force is api plied by the momentum of the machine to ctl'ect the stoppage. The contact which is carried by the sh: ft or drinn is yielding' so as to prevent nndne shock and to secure the application of the braking force in a pro-- gressivc manner. lVith the described parts is combined a power unconpler in the nature of a belt shifter which may shift a belt pin.

to a loose pulley. A single means or control part serves in one operation for uncoupling the power and adjusting the brake device so that the lugs cooperate to bring about a prompt yet comparatively easy and shockless lstoppage in which invariably the stitching mechanism or other parts of the machine will be brought to rest in a predetermined position or point.

At the right extremity of the main shaft 10 is a hand wheel 22. Near the hand wheel is a loose belt pulley 23 adjacent to a fast belt pulley 24, which, for convenience, may be formed in one part with a drum 25 secured upon it, so as to rotate with the main shaft. A belt shifter 28 serves to couple or uncouple power from the main shaft, this being mounted at the end of a sliding rod 29 which is continuously pressed toward the right by spring 30, tending to normally hold the belt on the loose pulley. The spring 30 surrounds the second sliderod 41 pressing against a yoke on the latter so as to move both slide rods to .the right, the two rods being connected by a swinging arm 32 pro'- jecting downwardly from a cross shaft 33 which, at the front of the machine, has a second arm 34v provided with a handle 35 or a treadle rod 36, or both. By -now depressing the treadle rod or handle the arm 32 is swung to the left and the belt is shifted to thefast pulley, the release of the handle or treadle again restoring the belt to the loose pulley. y

. Cooperating with the interior surface of the vdrum 25 isa brake device which will now be described. This device includes a member or pin 39, which is shiftable endwise between its inoperative position to the left and its operative position to the right, in which latter position it eii'ects the braking of therdrum and shaft. The pin 39 is carried in its endwise movements by a yoke 40rigidly secured to the slide rod 41, the latter being adapted to oscillate slightly to permit swinging of the yoke and pin for a purpose that will be later described.

It is proposed, to move the slide 4l with or by the movement of the slide 29 which carries the belt shifter. Instead of rigidly connecting them it is preferred to employ the arm 32 for actuating them both; thus a stud 42 projects rearwardly from the arm 32 into a side recess in the slide rod 41.v

Thereby the brake pin 39 and thebelt shifter may be moved to the right or to the left in unison, and the belt shifter is given a greater extent of movement than the brake In effect the arm 32 and the arts which serve to move it constitute a single means for both uncoupling the power and shifting the brake pin endwise into operative position and vice versa.

The brake device comprises, as already stated, an .interior brake shoe 43. This is shown substantially in the form of a half ring,y and one end of it is pivoted by a short fulcrum shaft 44 to the frame of the ma- -chine in such position that the half ring lies within the hollow of the drum in rubbing contact therewith.

In all of the figures the parts are shown in their position when the machine is stopped. l

The fulcrum shaft 44. of the brake shoe permits the latter to be slightly swung so that it can be pressed into more or less intimate frictional engagement with the drum interior surface. 1

It will be understood that in the normal running of the machine the pin 39 rests over the free end of the shoe 43, but is held in its leftward or inoperative position. After the controlling treadle has been released, the springl 30 tends to move the slide rods to the right, but they are restrained until the proper point in the rotation of the shaft 10 by the fact that the arm 17 .on the slide rod 41 has its stud 19 blocked by the extension 50 of the cam 20. When the extension 50 has passed the stud 19, the slide rods move to the right and the stopping action commences.

When the parts have sprung to the right, as described, a cam 45 on the main shaft 10 comes into play to depress the yoke 40 by means of a contact screw carried by -the latter, as best seen in Fig. 2. The depi'ession of the yoke' forces downwardly the pin 39, carried by the yoke. and, as seen in Fig. 4, this causes the brake band 43.110 press against the drum, giving a sort of initial friction which very largely retards the shafts rotation during a fraction of a revolution.

The final retarding and stopping is to' be effected by means of a stop 46 carried by and rotating with the drum. This stop is preferably yielding. It is shown of the form having a leftwise projection carried .by a radial arm portion, whlch loosely surrounds the drum hub, and which, to the right of the drum partition.` is provided with a coiled spring 47 affording alimited` extent .of yielding with increasing resistance. It will be understood that the active portion of the stop 46 rotates in a path which lintersects'the path'of the pin 39, so that when the latter has been moved to its operative position for stopping the machine',

las shown in Fig. 5, the two4 areV adapted ,to

It will be understood that Fig. v5`

meet. is a view seen from the rear and that the terms right and left' must be reversely considered on that figure. Fig. 4, which is a left view of the interior parts, 'shows a clockwise rotation ofthe drum. It has already been explained that the point of time in which theslide rods and the pin 39 shiftv to the right is controlled by the cam 20.

vtA

The control is such that the pin may not jump into :its operative position until after the rotating stop lo has passed the position occupied bv the pin, so that the shaft remiired to make a substantial fraction of a revolution before the stop and pin actually do contact.

,lifter the stopping parts have shifted to the right and after the yoke 40 has beeny depressed by the cam i for applying initial retarding pressure on the brake shoe 43, the

' shaft rotation continues at rapidly reducvshoe 43,

ing speed until, after a fraction of a revolution. the pin 3.() is struck by the stop 4:6. Before the actual. striking, however, the pin 39 has been passed by a swinging lock 48 controlled by spring 4.9, the purpose of which is to prevent any substantial rebounding' of the shaft after 'the final stoppage. is soonas the stop i6 strikes the pin Si) the following ope ations occur: Vl he impact upon the stop finger increases the pressure ofA the latter upon the brake so as to largely increase the retarding effect upon the rotation of the shaft. .ilse the strong coiled springe? at once commences to yield and compress, thus imposing a quickly increasing pressure upon the stop -rlo, so that in turn the stop 46, acting through the pin 239. imposes incneasingl pressure upon the brake shoe. Finally, however, the extent of yielding of the stop M/lG is limited bythe slot in which it plays with thel result that at the end of the stopping operation there is a positive rigid stoppage, the brunt of which is takenby the brake shoe, so that at once the Aallready greatly retarded shaft is further restrained and brought positively to a definite stoppage in the position shown in the figures. Any tendency to rebound is checned by the lock i8 striking the pin 39.'

.lt will thus be seen that there has been described a stop mechanism embodying the features and attaining the objects and advantages referred to and further advantages will be apparent to those skilled in the art. Since many matters of arrangement, design, detail and other features may be varied without 4departing from the principles hereof, no limitation to such features is intended excepting so far specified in the appended claims.

What is claimed is:

l. ln combination, a rotary shaft, a shaft retarder, a rotating stop carried by the shaft, and a shifting device coperating with said retarder and stop adapted to be shifted relatively to both said retarder and stop into the path of the stop, whereby the stop may act through the device to appll the retarder, means for at will effecting the shifting of the device 'to effect stopl'iage, and automar neans to prevent its shifting at an c pointin nthe shafts rotation and a lock rotating` with the shaft cope1.ating with the device to prevent rebound.

2. ln combimition, a rotary hollow drum, means to rotate it, a brake shoe at the "interior surface of said drum extending over a substantial arc and having one end anchored, a rotating stop carried by and having a limited yielding` movement in the drum, and a shifting block or pin cooperating with said brake shoe and stop, located to contact the free end of said brake shoe and adapted to be shifted into the path of the stop, so that when struch thereby it will apply said brake shoe, whereby the shaft is retarded and. definitely stopped, means for at will effecting the shifting of the ,block to effect stoppage, and automatic means to prevent its shifting at an improper point in the shafts rotation and a lock rotating with the drinn coperat ing with the block to prevent rebound.

3. A stop mechanism for high speed machines including in combination with-a rotating shaft, a hollow drum fixed on said shaft, a brake member ywithin the drum adapted to act frictionally against the drum interior surface for retarding the shaft, a rotating stop member carried around with the shaft, a non-rotating stop member io cated to cause a pushing action on said brake member for applying the brake and adapted to be shifted into'the path of said rotating stop member and when struck thereby to transmit the. momentum to the brake member for retarding and nally stopping the shaft; and means for shifting said non-rotating stop member into the path of said rotating stop member at suitable times, one of said stop members fitted to yield under increasing resistance toi a limited extent, whereby increasing braking action 'is' effected terminated by a final positive stoppage in a definite shaft position, and the energy being dissipated by Vthe brake be tween the meeting of said stop members and the final stoppage.

4. A stop mechanism for high speed machines including in combination with a rotating shaft, a brake member for retarding the shaft, a rotating stop member carried around with. the shaft, a non-rotating stop member adapted to be shifted into the path of said rotating stop member and when struck thereby to transmit the momentum to the brake member for retarding and .finally stopping the shaft, a device actuable at suitable times for causing the shifting of said rotating stop, a guard .rotating with the shaft for restraining such shifting until thel rotating-stop is at a` point substantially in advance of the non-i-otati11g stop, and automatic means controlled by the shaft for applying an initial retin-ding effect inthe period between the actuation of said device and the impact of said stop members.

5. A. stop mechanism for high speed ina-v chines including in .combination with a rotating shaft, a hollow drum fixed on said shaft, a rigid, non-rotating, arc-shaped brake shoe located within the drum adapted to be pressed against the drum interior sur` face for retarding the shaft, a rotating stop projection located Within the drum and a non-rotating stop member adapted at suitable times to be shifted into a position between said rotating stop projection and said brake shoe, one of said members constructed to yield whereby the brake may take effect between the time of impact and the iinal stoppage. v l y 6. A stop mechanism for high speed ma chines including in combination with a rotating shaft, a hollow drum fixed on seid 4face for retarding the shaft, a projection;4 locatedv within the shaft, a rigid, non rotating, arcshaped brake shoe located within the drum adapted to be pressed lagainst the drum interior surrotating stop drum and a non-rotatingstop member adapted .at suitable times to be shifted into a position between said rotating stop projection and said brake shoe, said stop projection being mounted to resiliently yield to a limited extent with relation to said drum.

In testimony7 whereof I aiix my in presence of two witnesses. JOHN KIEWICZ.

Witnesses z F.'A. SHEA,

DONALD CAMPBELL.

signature l 

